benzeneseleninic anhydride in diethylene glycol dimethyl ether T=120°C; 19 h;

1: I2 / 1 h / Heating 2: methanol / 1 h / Heating 3: 1.) Al(i-PrO)3, 2.) Supercel, Darco KB / 1.) toluene, cyclohexanone, reflux, 1 h, 2.) toluene, cyclohexanone, water, 15 min 4: 1.71 kg / 10percent KOH / methanol / Heating 5: 1.) pyridine, oxalyl chloride / 1.) toluene, RT, 1 h, 2.) toluene, 0.5 h 6: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 7: NH3 / ethanol / 8 h / 180 °C 8: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 9: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 10: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 11: 67 mg / NaIO4 / methanol; H2O / 2.5 h 12: toluene / 2.5 h / Heating View Scheme

1: 1.) Al(i-PrO)3, 2.) Supercel, Darco KB / 1.) toluene, cyclohexanone, reflux, 1 h, 2.) toluene, cyclohexanone, water, 15 min 2: 1.71 kg / 10percent KOH / methanol / Heating 3: 1.) pyridine, oxalyl chloride / 1.) toluene, RT, 1 h, 2.) toluene, 0.5 h 4: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 5: NH3 / ethanol / 8 h / 180 °C 6: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 7: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 8: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 9: 67 mg / NaIO4 / methanol; H2O / 2.5 h 10: toluene / 2.5 h / Heating View Scheme

1: 1.71 kg / 10percent KOH / methanol / Heating 2: 1.) pyridine, oxalyl chloride / 1.) toluene, RT, 1 h, 2.) toluene, 0.5 h 3: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 4: NH3 / ethanol / 8 h / 180 °C 5: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 6: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 7: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 8: 67 mg / NaIO4 / methanol; H2O / 2.5 h 9: toluene / 2.5 h / Heating View Scheme

1: 1.) pyridine, oxalyl chloride / 1.) toluene, RT, 1 h, 2.) toluene, 0.5 h 2: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 3: NH3 / ethanol / 8 h / 180 °C 4: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 5: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 6: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 7: 67 mg / NaIO4 / methanol; H2O / 2.5 h 8: toluene / 2.5 h / Heating View Scheme

1: methanol / 1 h / Heating 2: 1.) Al(i-PrO)3, 2.) Supercel, Darco KB / 1.) toluene, cyclohexanone, reflux, 1 h, 2.) toluene, cyclohexanone, water, 15 min 3: 1.71 kg / 10percent KOH / methanol / Heating 4: 1.) pyridine, oxalyl chloride / 1.) toluene, RT, 1 h, 2.) toluene, 0.5 h 5: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 6: NH3 / ethanol / 8 h / 180 °C 7: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 8: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 9: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 10: 67 mg / NaIO4 / methanol; H2O / 2.5 h 11: toluene / 2.5 h / Heating View Scheme

1: 87 percent / Na2CO3, NaIO4, KMnO4 / 2-methyl-propan-2-ol; H2O / Heating 2: NH3 / ethanol / 8 h / 180 °C 3: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 4: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 5: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 6: 67 mg / NaIO4 / methanol; H2O / 2.5 h 7: toluene / 2.5 h / Heating View Scheme

1: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 2: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 3: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 4: 67 mg / NaIO4 / methanol; H2O / 2.5 h 5: toluene / 2.5 h / Heating View Scheme

1: NH3 / ethanol / 8 h / 180 °C 2: H2 / PtO2 / acetic acid / 3 h / 25 - 60 °C / 2327.2 Torr 3: 1.) dimethyl sulfate, 2.) K2CO3 / 1.) CHCl3, reflux, 5 h 4: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 5: 67 mg / NaIO4 / methanol; H2O / 2.5 h 6: toluene / 2.5 h / Heating View Scheme

1: 1.) LDA / 1.) THF, -78 to 0 deg C, 5 min, 2.) THF 2: 67 mg / NaIO4 / methanol; H2O / 2.5 h 3: toluene / 2.5 h / Heating View Scheme